Closed due to Inactivity

I just tried to make an online purchase on a credit card (that I don't use often). I entered the card number and all information on the website, clicked "process order" and got a message that said card information was invalid.

So I called the credit card and listened to the recorded lady that gives account information: amount due zero, balance zero, available credit zero.

I immediately press zero and speak to the operator to find out why my available credit was zero. She casually says "my records show this card was closed due to inactivity". I paused, collected myself and said "was I notified of this?" She calmly says "No, Citi did not notify customers of card closures due to inactivity". So I politely gave her my two cents and asked her to pass the information along to the appropriate people. She said she would.

What if this was my one and only card that I had for emergencies? What if I were to find myself stranded somewhere and this card is the only way to get help, so I try to use it and can't because I was not notified of it's closure and therefore was not able to make alternate back up plans? No consideration. No consideration at all.